Re: [PATCH 29/32] drm/i915/display: Handle dedicated external ports in intel_encoder_is_tc()

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 15 Oct 2025, Gustavo Sousa <gustavo.sousa@intel.com> wrote:
> Quoting Jani Nikula (2025-10-15 12:33:31-03:00)
>>On Wed, 15 Oct 2025, Gustavo Sousa <gustavo.sousa@intel.com> wrote:
>>> @@ -1863,6 +1873,13 @@ bool intel_encoder_is_tc(struct intel_encoder *encoder)
>>>  {
>>>          struct intel_display *display = to_intel_display(encoder);
>>>  
>>> +        if (intel_encoder_is_dig_port(encoder)) {
>>> +                struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
>>> +
>>> +                if (dig_port->dedicated_external)
>>
>>Why go through all the trouble of duplicating the "decicated external"
>>information in the digital port, when you already have encoder
>>available, and can just use intel_bios_encoder_is_dedicated_external()
>>right here?
>
> I believe the last paragraph of the commit message explains the why.
> Are you suggesting that we handle the lifespan issue right in this
> series instead?
>
> Using intel_bios_encoder_is_dedicated_external() my first approach, but
> then we were hit with an oops because the VBT data was not available
> anymore in the driver unbind path.

Ugh. I think this deserves a comment, perhaps accompanied with a FIXME,
not just a mention in the commit message.

BR,
Jani.


-- 
Jani Nikula, Intel